Replacement Athearn Bombardier BiLevel Trucks, aka making the train roll

[Dwight in Toronto]

Yeah, after posting the above I removed the shell, and Craigolo is right … there is no wiggle room in which to add any appreciable weight.  I suppose there are other possibilities such as traction tires and/ or that frog snot stuff, but I’m not big on either of those.

When all is said and done, it looks like finding replacement trucks is the only viable option.  But … which ones???

[craigolio1]

A heavier locomotive would help. I haven’t investigated the Kato MP36. I wonder if it’s heavier and if so, could the chassis be fitted under the Athearn F59 shell? And then with investment and effort… how much would it help? I guess if we compared weights, found the difference, stack that much on the Athearn and see if it changes things?

[Dwight in Toronto]

Just last night I did a quick-&-dirty weight test on the Athearn loco. I used tiny bits of sticky-tac, and gradually added 4” strips of plumber’s solder (the heavy stuff that’s 1/8” diameter and is used to sweat joints on copper pipe etc) to the shell exterior.

Started with a strip along the bottom edge of each side (ie - just above the fuel tanks and trucks). I then added two more on the roof, and then two more again on the roof, for a total of six 4” strips of solder weights. I had no way to actually measure/quantify the weight change, but my rough guess is that I was probably close to doubling the original weight.

Net result?  The grossly overburdened little loco DID manage to pull all six crappy coaches around the oval, but not without STILL suffering some wheel spin on the curves.

So, I’ve decided “screw it”.  I just picked up two packets of Microtrains “4-wheel Lightweight Passenger Car Trucks” (1017) and will finangle them onto two coaches to see what happens. I’m beyond caring about the prototypical truck appearance. No one who views my layout will ever know any different (mostly four little grandkids, their parents, my wife, the odd brother- or sister-in-law etc).

At this point, some ten years down the road, I’d rather see the F59HPI pulling six cars having plain black conventional trucks on them, rather than a maximum of only three cars which happen to have shiny brake rotors like the real thing!

[craigolio1]

Just last night I did a quick-&-dirty weight test on the Athearn loco. I used tiny bits of sticky-tac, and gradually added 4” strips of plumber’s solder (the heavy stuff that’s 1/8” diameter and is used to sweat joints on copper pipe etc) to the shell exterior.

Started with a strip along the bottom edge of each side (ie - just above the fuel tanks and trucks). I then added two more on the roof, and then two more again on the roof, for a total of six 4” strips of solder weights. I had no way to actually measure/quantify the weight change, but my rough guess is that I was probably close to doubling the original weight.

Net result?  The grossly overburdened little loco DID manage to pull all six crappy coaches around the oval, but not without STILL suffering some wheel spin on the curves.

So, I’ve decided “screw it”.  I just picked up two packets of Microtrains “4-wheel Lightweight Passenger Car Trucks” (1017) and will finangle them onto two coaches to see what happens. I’m beyond caring about the prototypical truck appearance. No one who views my layout will ever know any different (mostly four little grandkids, their parents, my wife, the odd brother- or sister-in-law etc).

At this point, some ten years down the road, I’d rather see the F59HPI pulling six cars having plain black conventional trucks on them, rather than a maximum of only three cars which happen to have shiny brake rotors like the real thing!

I hear you. I hate shelf queens.

[daniel_leavitt2000]

I did a quick test on an incline track and found the Comets do run much better than the Kato Amfleet cars.

They seem to roll about 20-25% better. And about 4X better than the modified Bachmann Amfleet cars. Yikes! I don't have the Athearn bi-levels to compare it to.

One interesting note... I polished the wheels and axles of one Comet truck and found it to be more resistant than the non-treated comet truck. I have not treated the bearing cut yet so that may be the reason, but I would have thought any polishing would improve rolling qualities.

I did buy two additional cars - Con-DOT to replace broken parts on my MBTA cars as well as provide parts for experimenting on these trucks to get them to run better.

[peteski]

I did a quick test on an incline track and found the Comets do run much better than the Kato Amfleet cars.

They seem to roll about 20-25% better. And about 4X better than the modified Bachmann Amfleet cars. Yikes! I don't have the Athearn bi-levels to compare it to.

One interesting note... I polished the wheels and axles of one Comet truck and found it to be more resistant than the non-treated comet truck. I have not treated the bearing cut yet so that may be the reason, but I would have thought any polishing would improve rolling qualities.

I did buy two additional cars - Con-DOT to replace broken parts on my MBTA cars as well as provide parts for experimenting on these trucks to get them to run better.

@daniel_leavitt2000

Could you perform another test for me (since you have a good setup for this test)?  Disassemble the Kato Amfleet trucks and remove all the lubricant (Naphtha, lacquer thinner, or acetone, are perfect for degreasing), then test how well they roll.  I suspect that the lubricant dampens their rolling ability.  I think that is why Rapido doesn't lubricate them.

[Dwight in Toronto]

Finally, success with a single Athearn F59 loco pulling six Bombardier bilevel passenger cars.

As mentioned above, I picked up a couple packets of Microtrains passenger trucks (kit 1017).  After assembly, the shank is maybe 1 or 2 mm longer than the Athearn truck, and although the fit on the under-car truck mounting stem is a tiny bit on the loose side, the stock retaining screw does hold the MT truck in place. 

Just out of curiosity, I quickly tossed together a 3 foot long incline with roughly a 3% grade, and let fly with a stock, crappy-rolling OEM coach.  It was a slow crawl down the incline, with a couple of finger nudges as well. I then tried the coach that had just received the new MT truck … that’s right - just a single MT truck on one end, and the crappy stock truck on the other end. Suffice to say that this “hybrid” coach literally flew down the test ramp.

Based on this encouraging result, I outfitted five of the six cars with this hybrid truck arrangement. I left the sixth coach in it’s original despicable rolling condition. Even so, I’m pleased to say that the F59 loco actually pulled all six cars with no wheelspin whatsoever.  For me, this is the first time that this has ever happened.

One slight downside - the MT trucks can’t accomodate my 12 3/4” radius test oval because the wider truck frame hits the coach body shell.  The coaches did however work fine on a 19” radius curve.

With a successful test under my belt, I’ll be picking up enough MT trucks to replace all of the poorly designed Athearn units. It’s nice to finally see a reasonably lengthy GO Transit get-up work the way one expected it to ten years ago. In fact, I suspect that a 9 car train might even be possible on a layout without grades.

[peteski]

MTL makes inside-bearing MTL trucks?

But seriously, if you don't mind losing the unique look of the prototype trucks, any Micro Trains truck will run as well as if it was sliding on ice.  That is not surprising at all. I am however surprised that changing just one truck made such difference.

[Angus Shops]

I’ve always thought inside bearing trucks looked anemic anyway (literally - an iron deficiency).

Seriously, getting your cars to operate with the wrong trucks is better than not having them operate at all.

[peteski]

I’ve always thought inside bearing trucks looked anemic anyway (literally - an iron deficiency).

Seriously, getting your cars to operate with the wrong trucks is better than not having them operate at all.

I find it interesting that in this day and age, on one hand we (well, many modelers) literally count rivets or critique shade of paint on a model, but on other hand we are ok to change trucks to something totally unprototypical, to be able to run the models on the layout.    Not that there is anything wrong with that. 

[Dwight in Toronto]

Hey there Peteski, thanks for weighing in, because I always respect your comments.

Although I don’t consider myself a rivet counter, I DO have a very strong affinity, admiration and regard for prototypical details and accuracy replicated in miniature.  And I gotta tell ya … it took me a long time to make the change to those Bombardier coaches (over 10 years in fact).  I did so with some regret, since the original trucks do, admittedly, LOOK really nice.

Many times over the years I did online searches looking for corrective measures, to no avail. It was maybe five years ago while visiting an open house event at Scarborough Model Railroaders where I saw an Athearn F59 pulling nine coaches.  I asked the owner how the heck he accomplished that, and he said that he had to swap in Kato trucks (turned out that this fellow is one of the top tech guys at Rapido Trains). 

My most recent attempt to preserve the OEM trucks was the google search that brought me to this thread, and the impressive amount of R&D conducted by more accomplished folks than I, which still left things unresolved.  I feel that I have truly given this issue a fair shake; I’ve looked and waited patiently for solutions; in short, I’ve tried.  But after weighing all the pros & cons, I think Angus Shops summed it up best … for me, seeing six cars operating successfully with the wrong trucks is better than being limited to pulling only three coaches bearing the OEM trucks (or not operating them at all, which had been my situation for several years). Cheers.

[daniel_leavitt2000]

Well I did a bit of tinkering tonight:

Polished the wheels, bearings and plastic axle of the Rapido trucks with diamond paste (.25 micron) and Cape Cod Cloths. reinstalled in a stripped down Rapido truck - removing the brake shoes parts to avoid any contact.

Took apart a Kato Amfleet truck and washed with alcohol to remove lubrication.

I tested the trucks without car bodies as they are different weights and this could skew the test. They were tested with a grade, unscientifically, by nudging them with my finger.

The Kato truck was by far the best rolling truck of the group. It rolls almost as well as an outside bearing truck with metal wheels. This really surprised me, and proved Pete's theory right.

Next best rolling truck was the untreated Rapido truck. This rolls about 75% the distance of the Kato truck. Following this was the treated Rapido truck with about 50-65% the distance.

None of the trucks are what I would consider sleds. They all roll pretty well and I have a feeling that none should pose a problem with 5 car commuter sets.

As to why the Kato trucks roll better - I have a few theories.
1. The larger wheels create more angular momentum, keeping the wheel turning once in motion.
2. The thin wheel treads minimize contact area on the rail, reducing friction.
3. The bearing surface is minimized - a small blade of steel on a very thin axle.
4. The Rapido bearings may rub against the plastic axle if on a curve, causing increased friction.

Clearly my idea to polish the bearing and wheel surfaces didn't work out. Why is this? I'm not sure. Maybe the wheel coating also has some friction reducing properties?

Ideas to minimize friction on the Rapido trucks.
1. Adding graphite powder may help burnish the bearing surfaces, especially the plastic axle against the bearing.
2. Adding a Teflon thrust washer between the bearing and plastic axle.
3. Shortening the plastic axle enough so that it does not interfere with the bearing.
4. Adding a step inside the bearing to reduce the contact surface area with the axle.

Another idea would be to basically build a new truck:
1. Modify ESM wheels by cutting them in half, stubbing the ends and reducing the axle width to .75mm.
2. Use a jewel bearing that minimizes contact with the wheel face and axle.
3. Use an axle sleeve that does not touch the bearing surface under any conditions.

[nickelplate759]

Only partly relevant, but I attempted to improve the rolling qualities of the original Bachmann Amfleet trucks once, using graphite powder (Kadee Grease-em).  It helped a lot, but only for a short period of time, then they reverted to their original sled-like characteristics.

[peteski]

Thanks for verifying my idea about Kato trucks.  We usually think lubricants will decrease friction but they are also viscous (even light oil), and they dampen the movement.  This is even more pronounced with very small bearings, like in N scale trucks.

I agree with you that the (dry) Kato trucks roll so well because the axles are small the smallest diameter of the trucks you tested, and they are spinning in a relatively thin phosphor-bronze bearing. Kato also likely has the tightest tolerance of the bunch, and keeping everything aligned also minimizes friction.

I discovered the damping effect when playing with small ball bearings. They spun very freely when dry, but any lubricant (grease or even light oil) would impede their free spin.  But I also discovered that they spun the longest when lubricated with a very low viscosity fluid (Naphtha). But unfortunately it evaporates rather quickly.  That was an accidental discovery while I  was cleaning the lubricants out of the bearing.

I do like the idea of trying dry lubricant like graphite or Teflon. That might work.

The tread width IMO has no bearing on this. Only a very narrow area of the thread is on contact with the rail with any width tread.

Looking at the construction of the Rapido truck, I don't think that the plastic axle tube ever comes in contact with the brass bearing.  The bearing has a hollow area on its inner side to prevent that from occurring.  I think that the inside face of the wheel on the opposite side contacts its bearing before the plastic axle can come in contact with the bearing.

[mmagliaro]

Funny you mention this, as I just shot myself in the foot with this very concept (oil) on my little 1829 "Rocket" project.
Let's just say that with such a tiny, extremely light engine, you want everything spotlessly dry and clean.  Oil, even a drop of very light oil, just made it sticky and made the wheels drag.  So, after taking things apart and cleaning it all with acetone, it is back to it's dry, clean self.  I can't believe I even tried oil.  I always tell people not to try oil to fix *anything*.